Document handling apparatus and drive control

ABSTRACT

A document handling apparatus for use with a copying machine to copy either thin or thick documents. Two pairs of cooperating rollers located on top of the copying machine feed thin documents past an illuminating station. A carriage for supporting a thin or thick document is also located on top of the machine. For copying a thick document or for making multiple copies of a thick or thin document, the two pairs of cooperating feed rollers move out of the path of the carriage which travels across the illuminating station. The carriage is centered on its home position by a cam which is part of a slider bracket supporting structures. The slider brackets are manually or automatically raised and lowered. The rollers and the carriage are independently driven by the main motor of the copying machine through separate drive systems. Controls prevent the carriage from traveling too far in either direction and from moving when the feed rollers are in the path of the carriage.

BACKGROUND

1. Field of the Invention

This invention relates to a document handling apparatus for a copyingmachine, and, in particular, relates to a document handling apparatushaving separate means for moving a thick or a thin original documentacross the illuminating station of the copying machine.

2. Description of the Prior Art

In the field of copy machines, especially machines designed for a lowvolume of usage, there are several kinds of devices for handling singlesheet or thin-type documents as well as bulky or thick-type documents,such as books. One kind of device uses a fixed transparent platen onwhich both types of documents are positioned for copying. The documentis either scan exposed by a moving optical system or flash exposed.Unfortunately, moving optical systems are complex and expensive andflash exposure systems are bulky and so they require more machine spacethan is desirable for a low volume copy machine. Other copy machines usea fixed optical system and scan expose a document by moving it across anilluminating station. For example, one machine uses a reciprocatingcarriage for handling both thick and thin documents in transit across afixed illumination station. However, such a device is inherently slowsince no copying can be done during half the time that the carriage isin motion. Another machine permanently mounts feed rollers on oppositesides of a fixed illuminating station for handling single sheet, thindocuments which are rapidly fed across the illuminating station by thefeed rollers. But, with such a device, thick documents cannot be copiedat all.

Accordingly, it has been proposed to combine a reciprocating carriageand feed rollers into a single document handling apparatus in such a waythat the feed rollers do not interfere with the transit of the carriageand thereby obtain the benefits of both kinds of document handlers. Onesuch combination is shown in U.S. Pat. No. 3,728,015 where in oneembodiment a set of upper feed rollers are fixedly mounted to thecarriage and a set of lower rollers are mounted on the machine. Inanother embodiment of that device, both sets of rollers are fixedlymounted to the carriage. Other devices having thin original feed rollersmounted on a reciprocating carriage are also shown in U.S. Pat. Nos.3,790,272 and 3,740,133. Still another device that has feed rollersdetachably mounted to a carriage is shown in U.S. Pat. No. 3,806,239.Hence, when copying thick originals with one of the above devices, thethin document feed rollers are either removed by an operator or movedwith the carriage.

SUMMARY OF THE INVENTION

It is an object of this invention to provide a document handlingapparatus for a copying machine for handling thick and thin documents.

It is another object of this invention to provide a document handlingapparatus having a reciprocating carriage for handling thick and thindocuments and cooperating feed rollers for handling thin documentsindependent of the operation of the carriage.

It is still another object of this invention to provide a means formoving the cooperating feed rollers out of the path of the reciprocatingcarriage.

It is a further object of this invention to provide a means for loweringthe feed rollers out of the path of the reciprocating carriage.

It is a further object to automatically move the feed rollers out of thepath of the carriage.

Another object of the invention is to provide a slider bracket and crankfor raising and lowering the feed rollers.

Another object of the invention is to provide a means for centering thecarriage in a home position so that the feed rollers may be easilyraised.

It is also an object of the invention to independently drive thereciprocating carriage and the feed rollers.

Another object of the invention is to provide an intermittent andreversible drive for the carriage and a pivotal drive for the feedrollers.

Another object of the invention is to provide controls for preventingthe reciprocating carriage from traveling beyond a forward position or ahome position.

Another object of the invention is to control the delivery of the outputof the copying machine motor to the reciprocating carriage dependingupon the position of the feed rollers.

The present invention is for a document handling apparatus for a copyingmachine having a frame and means mounted on the frame defining anilluminating station at which a document traversing the illuminatingstation is illuminated for making a copy of the document. Areciprocating carriage with a transparent platen supports either a thinor thick document in transit across the illuminating station. Means areprovided for moving the carriage along a path across the illuminatingstation for copying a document placed face down on the platen of thecarriage. Two pairs of cooperating feed rollers are normally positionedin the path of the carriage, one pair on each side of the illuminatingstation, where they feed a single sheet or thin document across theilluminating station. Means are provided for moving the cooperating feedrollers out of the path of the carriage when the carriage is used tocopy a document and for moving the feed rollers back to their normalposition after the carriage has completed its operation.

The cooperating feed rollers are lowered and raised into the copyingmachine by means of a pair of slider brackets. The slider brackets areslidably mounted on opposite sides of the copying machine frame. Theslider brackets have an inverted "h"-like structure with one elongatedupright member coupled to another shortened upright member by a thirdmember transversely disposed to the two upright members. The feedrollers are mounted between opposite, corresponding vertical members ofthe "h"-like slider brackets. A common crank shaft passes through thecopy machine and each slider bracket is coupled to the crank shaft by acrank in order to move the brackets in tandem with each other. When thecrank shaft is rotated in one direction, the slider brackets move thecooperating feed rollers out of the path of the carriage by lowering therollers into the copying machine. When the carriage has completed itsoperation, the crank shaft is rotated in the opposite direction to raisethe feed rollers back into their normal position.

The crank used to move the slider brackets is composed of an arcuatemember having one end pivotally coupled to the slider bracket and theother end pivotally coupled to an arm. The arm has an annular, rotatablebearing mounted on the crank shaft. The annular bearing is turnedmanually by a handle or by other means to raise and lower the sliderbracket. The arcuate member has a shoe extending from the member towardthe slider bracket. As the crank shaft is rotated in one direction theshoe abuts against the slider bracket to restrain further motion in thatdirection. This provides a snap-over-center type device which ensures apositive location for the cooperating feed rollers in either the raisedor lowered position.

Other means for turning the cranks include an auxiliary motor that iscoupled to the crank shaft. The motor is actuated by the carriage copyselection control. When the carriage copy mode is selected by anoperator, the motor is energized and turns the cranks in one directionuntil the feed rollers are moved out of the path of the carriage andinto the copy machine. Upon completion of the use of the carriage copymode, the motor automatically turns in the opposite direction to returnthe feed rollers to their normal position.

Means are also provided for precisely positioning the carriage in itshome position. At least one elongated upright slider bracket member hascamming surfaces on both its upper sides. Corresponding camming surfacesare located on the carriage frame along that portion of the frame thatborders on the opening through which the rollers pass through the frame.If the carriage is slightly off center from the home position, a sliderbracket camming suface will engage the corresponding carriage cammingsurface and the carriage will be urged into its home position.

The invention also includes separate and independent means fordelivering the output of a motor to the feed rollers and to thereciprocating carriage. To drive the feed rollers, an output shaft of amain copy machine motor is coupled to a sprocket which is coaxiallymounted with a first spur gear. A second spur gear is in mesh with thefirst spur gear and is coaxially mounted with a primary roller drivesprocket. Each pair of feed rollers has a secondary roller drivesprocket that is coupled to the primary roller drive sprocket by aflexible belt that can pivot about the primary roller drive sprocket asthe rollers are lowered and raised.

The reciprocating carriage is driven off of a main drive chain whichdelivers power from the main motor to other elements of the copyingmachine. The main drive chain passes under a sprocket coaxially mountedwith a forward clutch and over another sprocket coaxially mounted with areturn clutch. The forward and return clutches are coupled by an endlessbelt to a pinion that meshes with a rack mounted on the carriage. Whenthe forward clutch is engaged the pinion turns in one direction to drivethe carriage forward; when the return clutch is engaged, the pinionturns in the opposite direction to return the carriage to its homeposition. By passing the main drive chain over one clutch and under theother and alternately engaging the two clutches, reciprocating motion isdelivered to the carriage without the need for reversing the directionof the motor.

Controls are provided for preventing the carriage from transiting beyonda predetermined path between the home position and the forward position.The operation of the forward and return clutches is governed by acontroller that also governs the timed, sequential operations of theother copying machine elements. Such controllers are well known in theart and may include electro-mechanical, relay-type logic controls orsolid-state, integrated control circuits. The controller contains atiming and switching system for alternately energizing the clutches todrive the carriage a predetermined distance between a home and a forwardposition and back to the home position.

As the carriage approaches either the forward position or home position,the controller disengages the appropriate clutch and the carriage coaststo a stop due to the drag exerted by the endless belt which couples thepinion to the clutches and other frictional forces exerted on thecarriage by its frame mountings. If there is a malfunction and thecarriage is driven beyond the predetermined distance, then an endsensing switch senses that the carriage has traveled its full distanceand will disengage whichever clutch is engaged and thereby allow thecarriage to coast to a stop. When the carriage stops in its forwardposition, it will remain there until the timing and switching system ofthe controller energizes the return clutch. The carriage will remain inthe home position unless it is accidentally advanced. Then the endsensing switch will energize the return clutch to drive the carriageback to its home position.

Another pair of sensing switches senses whether the rollers are in theirnormal position or in their lowered position. If the rollers are intheir normal position, means responsive to the sensing switches will notpermit energizing of the clutches so the carriage will not move when thefeed rollers are in their normal position.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a copying machine including the invention.

FIG. 2 is a partial perspective view of the reciprocating carriage andfeed rollers of the invention.

FIGS. 3 and 4 are perspective elevations of the means for raising andlowering the feed rollers.

FIG. 5 is a partial perspective elevation showing the drive means forthe feed rollers.

FIG. 6 is an elevation view showing the carriage drive means with thecarriage at its home position.

FIG. 7 is an elevation view showing the carriage drive means with thecarriage at its forward position.

FIGS. 8 A-F are partial elevations showing the mechanical means forpositioning the carriage.

FIGS. 8 G-H are partial elevations showing a switch for sensing when thecarriage is at its home position.

FIG. 9 is a partial perspective elevation showing an alternateembodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The preferred embodiment of the invention is shown in FIG. 1 inconnection with a copying machine 10. While those skilled in the artunderstand the general operations of copying machines, the followingdescription of copying machine 10 will supplement that understanding inso far as the instant invention is concerned. The copying macine 10 is aplain paper copier similar to the machine described in U.S. PatentApplication Ser. No. 670,253, now U.S. Pat. No. 4,084,901. A documenttransiting the illuminating station 20 is illuminated by exposure lamps22 A,B. The illuminated image of the document passes through exposureslit 24 comprising a glass or another transparent material. The image ofthe document is reflected by mirror 25 into a lens 1 where it isreflected by another mirror 2 back through lens 1 onto a portion of aphotoconductive web 66 at imaging station 27.

A photoconductive web 66 consists of a photosensitive upper layercomprising zinc oxide bonded to a conductive substrate. Thephotoconductive web 66 is wound between a supply reel 63 and a take-upreel 64. In a timed relationship with the transit of the document, thephotoconductive web 66 moves from the supply reel 63, past idler roller68 and corona charger 70 which imparts a uniform electrostatic charge tothe photosensitive layer. The uniformly charged web 66 travels throughthe imaging station 27 where light and dark areas of the reflected imagestrike the web 66. The light struck areas of the photoconductive web 66are discharged and the dark areas (corresponding to the indicia of thedocument) retain their charge.

Next the photoconductive web 66 passes a developer 99 where magneticallyattractive toner particles 100 are picked up by a magnetic brush 98 andare brought into contact with the photoconductive web 66. Tonerparticles 100 are attracted and adhere to the charged areas ofphotoconductive web 66 and continue to move with the web toward transfercorona 76. Simultaneously, a copy sheet 8 is withdrawn from paper supply94 and is fed by copy sheet supply rollers 95, 96 across the transfercorona 76. Toner particles 100 are attracted from the web 66 to the copysheet 8 by the transfer corona 76. Endless belt 79 feeds the copy sheet8 into and through fuser 90 where the toner particles 100 adhering tocopy sheet 8 are permanently fixed thereon. Finally, the copy sheet 8,bearing indicia duplicating the original, is discharged from the copymachine 10 by discharge rollers 92, 93. Meanwhile, the photoconductiveweb 66 continues to move towards takeup reel 64 and in doing so passescleaning corona 78 which discharges any residual charge onphotoconductive web 66. A soft bristle brush 80 removes any remainingtoner particles from the photoconductive web 66 and those particles arevacuumed away by vacuum 82 into collector bag 84.

The control of the various operations described above in addition tofurther operations that are described hereinafter is accomplished bycontroller 104. The controller may consist of the relay logic systemdescribed in U.S. Patent Application Ser. No. 670,253 or may includesolid state, integrated circuit logic or a microprocessor that are wellknown in the art of electrophotocopying.

The document handling appartus includes a reciprocating carriage 14 forcarrying thick documents and for making continuous multiple copies ofthick or thin documents. Referring to FIGS. 1 and 2, carriage 14 isslidably mounted on the frame 12 of copying machine 10. Carriage 14includes a transparent platen 7 upon which a thick document such as book6 is placed face down. In its transit across illuminating station 20,one side of carriage 14 is guided by annular slide bushings 108 a,bwhich are mounted on the carriage 14 and slide along guide shaft 106.The other side of the carriage 14 slides along a rail (not shown) thatis mounted on the upper surface of frame 12.

The document handling apparatus also includes a thin document feeder 15which has two pairs of cooperating feed rollers 16 a,b and 17 a,b.Rollers 16 a,b and 17 a,b are shown in their normal, feeding position inFIG. 2. Rollers 16 a, b are on one side of illuminating station 20 androllers 17 a,b are on the opposite side of the illuminating station 20.Rollers 16 a,b are biased together by springs 112 a,b and rollers 17 a,bare similarly biased together by springs 113 a,b. Rollers 16 a,b and 17a,b extend between and are supported by slider brackets 18, 19. Arm 179of an on-off switch 178 is disposed near the nip of rollers 16 a,b andarm 181 of a sequencing switch 180 is disposed downstream of that nip.Lower rollers 16b and 17b are rotatably mounted between the sliderbrackets 18, 19. Upper rollers 16a and 17a are slightly verticallymovable within the limits of their respective movable mounts 110 a,b and111 a,b. This enables the thin original feeder 15 to handle thinoriginals of varying thicknesses and allows an operator to raise theupper rollers to clear a paper jam.

Brackets 18, 19 are slidably mounted on opposite sides of frame 12 ofcopying machine 10. Brackets 18, 19 support the feed rollers 16a,b and17a,b. As best shown in FIG. 5, bracket 18 comprises a short uprightmember 18a, a long upright member 18b and a transverse member 18c whichcouples members 18 a,b together into a unified inverted "h"-likestructure. Bracket 19 is similarly comprised of a short upright member19a, a long upright member 19b and a transverse member 19c. Feed rollers16 a,b are mounted between the upper portions of slider bracket members18b, 19b and feed rollers 17 a,b are mounted between the upper portionsof slider bracket members 18a, 19a. Secondary drive sprocket 47 ismounted coaxially with roller 16b, the axis of which projects throughlong member 18b, secondary drive sprocket 49 is similarly mounted on theaxis of roller 17b that projects through short member 18a. It will beappreciated by those skilled in the art that bracket configurationsother than the inverted "h"-like structure of the preferred embodimentcould be used to support the cooperating feed rollers 16a,b and 17a,b inthe orientation described above.

Turning to FIGS. 3 and 4, there are shown means by which the feedrollers 16a,b and 17a,b are lowered out of their normal raised positionsby a crank 114 that is coupled to bracket 19. The crank 114 has anarcuate link 116 with one end rotatably mounted on shaft 115 that isfixed to bracket 19. The other end of arcuate link 116 is coupled to anarm 118 by a connecting shaft 117. Arm 118 is journaled about crankshaft 127 which passes through the frame of the copying machine andterminates in the journal of an arm 119 of crank 214 (FIG. 5) that issimilarly coupled to roller support bracket 18. By turning the crank 114about its shaft 127, the roller brackets 18 and 19 are respectivelylowered and raised out of and into their normal position.

As shown in In FIG. 3, the rollers are manually raised and lowered byturning handle 140. Crank shaft 127 is terminated in a pulley 139 whichis coupled to handle pulley 138 by endless belt 134 which passes overidler pulleys 136 and roller 137. Handle shaft 141 is coaxial withhandle pulley 138 and handle 140 so that as the handle 140 is turned inthe direction indicated by arrow 145 the slider brackets 18, 19 areraised. When the handle is turned in the opposite direction, sliderbrackets 18, 19 are lowered.

However, unless otherwise restrained, arcuate link 116 would continue totravel past the position indicated in FIG. 4, thereby lowering theslider brackets 18, 19 if handle 140 continued turning. To prevent thisfrom happening and to provide a stable, normal position for rollers 18,19, the crank 214 associated with support bracket 18 has a restrainingshoe 132 extending from the arcuate link 116 towards the support bracket18 such that the restraining shoe 132 will abut against support bracketmember 18b when the rollers are in their raised position and therebyprevent further motion of the crank. The location of the shoe 132 on thearcuate link 116 and the attachment of the arcuate link 116 to thebracket 18 are chosen such that arms 118 and 119 will travel in thecounter-clockwise direction slightly past a twelve o'clock position forpositioning the slider brackets 18, 19 in the normal position.Similarly, when the brackets 18, 19 are lowered, the shoe 132 abutsagainst member 18b again to establish a stable lower position. Sinceshoe 132 restrains the motion of the arcuate link in either direction,the slider bracket assemblies 18 and 19 will have only two stablestates, the normal or raised position and the lowered position.

Delivery of the output of main motor 36 to the rollers 16a,b and 17a,bis best shown in FIG. 5. The output of main motor sprocket 38 is coupledto roller sprocket 42 and outer carriage sprocket 41a by endless drivechain 40. Outer and inner carriage sprockets 41a,b are mounted on acommon shaft. Coaxially mounted with roller sprocket 42 is a first spurgear 128 that is in mesh with a second spur gear 129. Roller drivepulley 50 is mounted coaxially with second spur gear 129 and any driveimparted to pulley 50 by spur gear 129 is transmitted to driven rollerpulleys 47 and 49. Driven roller pulleys 47 and 49 are respectivelycoupled to one end of rollers 16b and 17b. The drive imparted to spurgear 129 is coupled to driven roller pulleys by an endless rollerdriving belt 48 whose path passes over driven pulleys 47, 49, underpulleys 51a,b and over idler pulleys 51c,d. Idler pulleys 51a,b are arerotatably mounted on slider bracket 18. Idler pulleys 51d,c arerotatably mounted on member 18c and are respectively positionedunderneath idler pulleys 51a,b. Spur gear 129 and drive pulley 50 aremounted on a post 126 that passes through a slot 125a in roller bracketmember 18b. In this manner, spur gear 128 and 129 remain in mesh androller drive belt 48 pivots around pulley 50 as the bracket 18 is raisedand lowered.

The delivery of drive to the reciprocating carriage is also partiallyshown in FIG. 5 and more completely shown in FIGS. 6 and 7. Endless maindrive chain 44 transmits the drive from inner carriage sprocket 41b toclutch sprockets 57, 55. Sprocket 57 is on a common axis with forwarddrive clutch 58; likewise sprocket 55 shares a common axis with returndrive clutch 56. Main drive chain 44 passes over return clutch sprocket55 and under forward clutch sprocket 57. Main drive belt 44 drives othercomponents of the copy machine including the toner assembly and thephotoreceptor web, but for purposes of this invention, it is onlynecessary to show how the main drive belt drives the carriage copy andreturn clutches 56 and 58. Hence, the main drive belt 44 is shown toturn about two idler sprockets 45a,45b. An endless carriage belt 61couples the two clutches 56, 58 to pinion 54. Tension to the carriagedrive belt 61 is supplied by idler pulley 60. Pinion 54 meshes with arack gear 52 that is mounted on the underside of the carriage 14. Inthis manner, motor 36 need only turn in one direction and thereciprocating motion for carriage 14 is derived by intermittently andalternately energizing clutches 56, 58 as described below.

After the brackets 18, 19 are moved out of the path of the carriage asshown in FIG. 7, the carriage is ready to reciprocate. For a forwardstroke, forward clutch 58 is energized, thereby causing the pinion 54 toturn in a clockwise direction to move the carriage forward. Atcompletion of the forward stroke, clutch 58 is de-energized and clutch56 is energized thereby imparting a counter clockwise motion to pinion54 to return carriage 14 to its home position whereupon return clutch 56is de-energized.

The invention also includes means for centering the carriage in the homeposition when the rollers are raised to their normal position. Referringto FIGS. 8 A-F, there is shown the upper portion of slider bracket 18and a portion of carriage 14 containing an opening 146 through whichslider bracket 18 passes to position rollers 16a,b and 17a,b in theirnormal position. The carriage 14 is in its home position when theopening 146 in the body of the carriage 14 is over the slider brackets18, so that brackets 18, 19 may move up through opening 146 to itsnormal position through passage 146. However, if the carriage 14 isslightly forward of the home position as in FIG. 8a, then a portion ofthe carriage will overlie slider brackets 18, 19 and tend to inhibit thebrackets from rising to their normal position. To avoid that undesirableresult, at least one bracket, bracket 18, is provided with a firstcamming surface 150 which cams off of a corresponding carriage cammingsurface 14a as shown in FIGS. 8b,c,d to center the carriage 14 in itshome position by moving the carriage a short distance to the rear.Similarly, if carriage 14 is too far to the rear of the home position asshown in FIG. 8e, then second camming surface 152 of bracket 18 will camoff of another corresponding carriage surface 14b as shown in FIG. 8f,in order to move the carriage slightly forward as bracket 18 is raised.

Operation of the copy machine is governed by a controller 104 whichsequentially activates the copy machine components in order tocoordinate the operation of each one with the other. Controller 104 iselectrically connected to and receives input signals from verticalposition sensing switches 26 and 28 (FIGS. 1 and 9), end sensing switch30 (FIG. 1) carriage synchronizing switch 35 and paper feed switches178, 180 (FIG. 5). Forward sensing shoe 32 and home sensing shoe 34 aremounted in line on the underside of carriage 14 for acting upon endsensing switch 30 as hereinafter described. Synchronizing shoe 37 isalso mounted on the underside of carriage 14 and slightly to one side ofthe line between shoes 32 and 34. Accordingly, synchronizing switch 35is likewise located out of the line of movement of shoes 32, 34 and inthe path of shoe 37. Those skilled in the art will appreciate how thefunctions of home sensing switch 30 and synchronizing switch 32hereinafter described can be combined by appropriate programming orwiring of controller 104.

The controller 104 is also electrically connected to, and receives inputsignals from the print button 182 and the copy count select dial 184. Inresponse to the various inputs, the controller operates main motor 36 aswell as clutches 56, 58 as follows. The copy machine 10 is normallydisposed to copy thin original documents, so roller brackets 18, 19 arein their normal, raised position, and upper vertical sensing switch 26is closed. In response to the closing of switch 26, controller 104renders the copying machine 10 ready to accept only thin sheet documentsfed through the cooperating feed rollers 16a,b and 17a,b. As a thinsheet document 5 (FIG. 2) is fed into the nip of input rollers 16a,b,the document 5 first closes paper switch 178. In response to the closingof paper switch 178, the controller 104 turns on the main motor 36 andthe feed rollers 16a,b and 17a,b begin to turn. As document 8 continuesinto the nip of the input rollers 16a,b is closes a sequencing switch180 disposed downstream of first paper switch 178. In response to theclosing of switch 180, controller 104 sequentially turns on and controlsthe other elements of the copier, including the corona chargers, theilluminating lamps 22a,b the toner magnetic brush 99, the copy paperfeed rollers 95,96, the fuser 90, etc. The various copy machine elementsare sequentially energized and operated in a manner well known in theart in order to deliver a finished copy after which the controller 104turns off motor 36 until another document is fed into the nip of theinput rollers.

Before an operator may use the carriage copy mode, the feed rollers haveto be lowered out of their normal position whereupon upper verticalsensing switch 26 opens and lower vertical sensing switch closes. Uponsensing that switch 28 is closed, the controller 104 is ready tosequentially energize clutches 56 and 58 in order to make copies withthe reciprocating carriage. Next, the operator presses a PRINT button182, and the controller 104 energizes forward electromagnetic clutch 58for a predetermined time during which it has been calculated that thecarriage 14 transits a sufficient distance to make a copy of a thickdocument, such as a book 6, which is placed face down on platen 7. Thetransit of carriage 14 is synchronized with the other elements of thecopier by controller 104 and carriage sychronizing switch 35 andcarriage synchronizing shoe 37. As the carriage 14 leaves the homeposition under the drive imparted to the carriage 14 by forward clutch58, carriage synchronizing switch 35 is closed by shoe 37 and switch 35sends a signal to controller 104 that then begins the timed, sequentialoperation of the copying process.

When carriage 14 reaches the forward position, controller 104deenergizes forward clutch 58, and carriage 14 comes to a stop due tothe tension that carriage drive belt 61 exerts on pinion 54 and theother frictional forces between the carriage 14 and the frame 12.Thereafter, controller 104 energizes electromagnetic return clutch 58 todrive carriage 14 to the home position. Similarly, return clutch 56 isalso energized for a predetermined time after which clutch 56 is turnedoff and the carriage comes to rest in its home position. The foregoingoperation of clutches 56, 58 is repeated for the number of copiesindicated on a copy count selector 184.

Under certain operating conditions, the predetermined transit times andthe actual transit times may differ. For example, if the line voltage isfluctuating the main drive motor 36 will exert more or less torque onoutput sprocket 38 than was counted on when the predetermined transittimes were computed. Accordingly, to account for these inconsistencies,end sensing switch 30 is provided for the purpose of turning offclutches 58 and 56 in the event that the controller as not already doneso by the time that the carriage 14 reaches either of the forward orhome positions. Another function of end sensing switch 30 is to helppositively position carriage 14 in its home position. End sensing switch30 cooperates with two switch actuating shoes, 32, 34, which are mountedon the carriage in line with sensing switch 30. When either of thesensing shoes 32, 34 closes end sensing switch 30, the electromagneticclutch that is driving the carriage will be deenergized.

For example, if controller 104 has not deenergized forward clutch 58 bythe time the carriage platen 7 passes illuminating station 20 thenforward sensing shoe 32 will close end sensing switch 30 and forwardclutch 58 will be deenergized. The carriage 14 will coast to a stopunder the influence of the frictional and inertial forces of the drivesystem. Similarly, end sense switch 30 will deenergize return clutch 56when home sensing shoe 34 closes switch 30.

In addition to the foregoing function, end sensing switch 30 alsocooperates with controller 104 to maintain carriage 14 in the homeposition when the copy machine 10 is idle. This function of sensingswitch 32 is shown in FIGS. 8G,H where the carriage 14 in FIG. 8g hasnot returned far enough to its home position, (i.e., return clutch 58was deenergized too early) so that it cannot be positively centered bythe camming action described above. Switch 30 is open because thepredetermined time for the carriage 14 to return has elapsed. In thisevent, the return clutch 56 will be energized again until the carriagehas been driven home to its position shown in FIG. 8h so that shoe 34closes end switch 30. A similar homing operation will occur in the eventthat a passerby accidentally offsets the carriage 14 from the homeposition.

An alternate embodiment of the invention is shown in FIG. 9 wherebrackets 18 and 19 are automatically raised and lowered by an auxiliarymotor 170 in lieu of the crank handle 140. Output sprocket 172 ofbracket motor 170 is coupled to shaft 127 by a sprocket 176 mounted onshaft 127 and a drive chain 174 running around sprockets 172, 176 bycontroller 104 in cooperation with vertical sensing switches 26, 27 andthe PRINT button 182. The carriage copy mode is selected by pressing thePRINT button 182 whereupon the motor 170 is turned on by controller 104in order to drive the brackets 18, 19 vertically downward until switch28 is closed at which time controller 104 shuts off motor 170. When thecarriage copy mode is completed and the desired number of copies havebeen made, controller 104 will automatically return brackets 18, 19 totheir normal positions by reversing the direction of motor 170 to raisebrackets 18, 19 until switch 26 is closed whereupon controller 104 turnsoff motor. An advantageous operation feature of the automatic embodimentis that the copying machine 10 is always ready to make a copy of eithera thin or thick document. The operator need only feed a thin documentinto the nip of input rollers a,b or place the thick document onto ofcarriage 7 and press the PRINT button. Nothing further need be done toplace the machine in its proper mode of operation.

What is claimed is:
 1. In a copying machine having a frame, meansmounted on the frame defining an illuminating station, a carriagemounted on the frame for carrying a thick or thin original documentalong a path across the illuminating station, cooperating feed rollersnormally positioned in the path of the carriage for feeding a thinoriginal document across the illuminating station, means for moving thecooperating feed rollers in a direction transversely out of the path ofsaid carriage, and a motor mounted on the frame for supplying a drivefor the carriage and the cooperating feed rollers, the improvementcomprising:carriage transmission means for delivering the output of themotor to the carriage for reciprocally driving the carriage when thefeed rollers are out of the path of the carriage and feed rollertransmission means for delivering the output of the motor to the feedrollers independently of both the carriage transmission means and theposition of the feed rollers.
 2. The copying machine of claim 1 whereinthe carriage transmission comprises means for intermittently andreversibly delivering the output of the motor to the carriage.
 3. Thecopying machine of claim 2 wherein the intermittent and reversibledelivery means comprisesa first clutch for turning in the direction ofthe motor when said first clutch is energized, a second clutch forturning in the opposite direction of the motor when said second clutchis energized, a chain driven by the motor and having one side of saidchain engaged with one clutch and the other side of said chain engagedwith the other clutch, means for alternately and sequentially energizingsaid clutches and, means coupled to the carriage and to said clutchesfor deriving a reciprocating movement for said carriage as the clutchesare alternately and sequentially energized.
 4. The copying machine ofclaim 3 wherein the means for deriving motion for the carriage comprisesa rack mounted on the carriage, a pinion rotatably mounted on the frameand engaged with the rack and an endless belt for coupling the pinion tothe two clutches.
 5. The invention of claim 2 further comprising meansresponsive to said carriage transmission means for automatically movingsaid feed rollers out of the path of said carriage when the output ofsaid motor is intermittently and reversibly delivered to said carriage.6. The copying machine of claim 5 further comprising means forautomatically returning said feed rollers to said normal position whensaid motor output to said carriage is terminated.
 7. The copying machineof claim 1 wherein said feed roller transmission is rotatably mounted onthe frame for movement with the rollers as they are moved into or out oftheir normal position.
 8. The copying machine of claim 7 wherein saidfeed roller transmission comprises a drive sprocket rotatably mounted onthe frame and coupled to the motor, a driven sprocket coupled to atleast one feed roller, and an endless chain trained about the drivesprocket for coupling the driven sprocket to the drive sprocket.
 9. Thecopying machine of claim 8 further comprising means for biasing thedriven feed roller against the other feed roller so that the rollerscooperate to feed a thin original document across the illuminatingstation.
 10. The copying machine of claim 9 wherein said biasing meanscomprises an endless coiled spring mounted in tension around saidrollers.
 11. In the copying machine of claim 1, the further improvementcomprisingmeans for sensing when the carriage is at a forward positionand at a home position, and means responsive to said sensing means forinterrupting the delivery of the output of the motor to the carriagewhen the carriage is at the forward position and at the home position12. The copying machine of claim 11 wherein said sensing means comprisesan end sensing switch and forward and home switch actuators mounted onthe carriage for actuating said end sensing switch when the carriage isrespectively in either the forward or the home position.
 13. In thecopying machine of claim 1, the further improvement comprisingmeans forsensing when the cooperating feed rollers are in the normal position;and means responsive to said roller position sensing means forinterrupting delivery of the output of the motor to the carriage whenthe rollers are in the normal position.
 14. The copying machine of claim13 wherein said roller position sensing means comprises a switchactuated by the means for moving the cooperating feed rollers when therollers are in the normal position.
 15. The copying machine of claim 13further comprising means for sensing when a document is fed into the nipof the cooperating feed rollers and means for energizing the motor inorder to drive the feed rollers.
 16. The copying machine of claim 13further comprising means for sensing passage of a thin document towardthe illuminating station and means responsive to said document passagesensing means for initiating the operation of the copying machineelements in the predetermined, timed, sequential order.